KVM: x86 emulator: fix unlocked CMPXCHG8B emulation

When CMPXCHG8B is executed without LOCK prefix it is racy. Preserve this
behaviour in emulator too.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b8ce53861f68684832ba041427068dd04b90335f..64c9854f0458ffde75105ad3e84dd1a893abf901 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1724,7 +1724,6 @@ static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
                       (u32) c->regs[VCPU_REGS_RBX];
 
                ctxt->eflags |= EFLG_ZF;
-               c->lock_prefix = 1;
        }
        return X86EMUL_CONTINUE;
 }